Bilge pump problem

thanks I will check the output and see if its spinning on the shaft, yes it is the corrugated type pipe, I have just lowered the bow on trailer to minimise the head of water..... still no luck, but I will follow up on your reccomended checks . The rain has set in here and I have now got wet and cold enough for the day so am having a breather until the rain stops
Boyd

with the hose disconnected the water pumps out of the Bilge pump Body Outlet and the hose is clear I can blow through it ) all I can come up with is its not pumping enough pressure to get it out ie the head of water in the pipe is defeating it .... but why ?

After sorting the rudder stuffing , bucket test ,then thermostat / impellor , then an LPG leak I am finally on the way to the lake today . Just before I go I check the Bilge pump On ......whirring ..... but not pumping out ( filled the bilge up with a hose first ) So I remove the pump check for any blockages detach the hose to the bow outlet back flush with a hose then blow through it, its all clear . I then Run the Pump with the hose disconnected and hey presto water pumps out . I reconnect it all switch the pump on manual and plenty of noise but nothing coming out of the Bowhole The only thing i would comment on is that the pump is noisier its screeching is it that its working but not developing enough pressure ???? what is causing the screeching ???? . What can i do next ??? Its now raining here in the UK and the forecast is rain every day for the next 5days I am really hacked off and want to live somewhere sunny